Schultz's Proposal for Finding Longitude at Sea

A critical discussion of this method of longitude determination is to be found, for example, in Rev. Pearson W. , An introduction to practical astronomy… , ii (London, 1829), 603–612.

The only account of Stender's life and work known to me is Kopelevich Yu Kh. Chenakal V. L. , “Gotthard Friedrich Stender and the Petersburg Academy of Sciences”, From the history of science and technology in the Baltic States (Riga, 1968), 81–98 [in Russian].

Ibid. 84.

Stender's answer is, in fact, 43°45′5′, since he first found the hourly lag of the Moon by dividing the daily lag of 12°46′15′ by 24 (= 30^m 50^a·4), and subsequently used the approximate value of this quantity (viz. 30^m50^B) in obtaining his result.

Tobias Mayer , “Novae tabulae motuum solis et lunae”, Commentarii Societatis Regiae Scientiarum Gottingensis , ii (1753), 383–430.

Forbes Eric G. , “Index of the Board of Longitude Papers at the Royal Greenwich Observatory, Part 1”, Journal for the history of astronomy , i (1970), 174. See vol. vi, P.R.O. Ref. 534, pp. 22–23.

Ibid. (Part 2), Journal for the history of astronomy , ii (1971), 65. See vol. xxvii (1), P.R.O. Ref. 562, pp. 3–32.

This point is made by Pearson, op. cit. (ref. 1), 605.

De Magellan Jean-Hyacinthe , “Mémoire sur la nouvelle construction des quarts de cercle à réflection, Connus sous le nom d'Octants & Sextants Anglois”, Description des octants et sextants anglois, ou quarts de cercle à reflection… (Paris, 1775). Cf. p. 120.

There is no evidence to suggest that either Stender or Schultz was aware of Pingré's work on this method prior to the publication of Stender's book in 1764.

De Lalande Joseph , Astronomie , iii (2nd ed., Paris, 1771), 798.

Ibid. , 799–800.

The foregoing summary of Pingré's method is based upon Lalande's account, ibid. , 795–8.

Ibid. , 795–800.

De La Caille Abbé , “Mémoire sur l'Observation des Longitudes en Mer, par le Moyen de la Lune”, Histoire de l'Académie royale des Sciences pour l'annèe MDCCLIX (Paris, 1765); Mémoires , 75–82.

This is why Schultz's proposal is classified as a lunar distances method in the official Index (cf. ref. 7).